UTERUS – UTERINE SARCOMAS (LEIOMYOSARCOMA, ENDOMETRIAL STROMAL SARCOMA, ADENOSARCOMA) (ICD‐O‐3 C53, 54, 55)

The definitions of the T, N, and M categories correspond to the FIGO stages. Both systems are included for comparison.

Rules for Classification

The classification applies to sarcomas except for carcinosarcoma, which is classified as carcinoma of the endometrium. There should be histological confirmation and division of cases by histologic type.

The FIGO stages are based on surgical staging. TNM stages are based on clinical and/or pathological classification.

Anatomical Subsites (Fig . 424)

Cervix uteri (C53)
Isthmus uteri (C54.0)
Fundus uteri (C54.3)

Histological Types of Tumours

Leiomyosarcoma	ICD‐O‐3 M 8890/3
Endometrial stromal sarcoma	ICD‐O‐3 M 8930/3
Endometrial stromal sarcoma, low grade Adenosarcoma	ICD‐O‐3 M 8931/3ICD‐O‐3 M 8933/3

Regional Lymph Nodes (Fig. 425)

The regional lymph nodes are the pelvic (hypogastric [obturator, internal iliac] (3), common (5) and external (4) iliac, parametrial (2), and sacral (6)) and the para‐aortic nodes (7).

Leiomyosarcoma, Endometrial stromal sarcoma

TNM Clinical Classification

T – Primary Tumour

TNM Categories	FIGO Stages	Definition
T1	I	Tumour limited to the uterus
T1a	IA	Tumour 5 cm or less in greatest dimension (Fig. 442)
T1b	IB	Tumour more than 5 cm in greatest dimension (Fig. 443)
T2	II	Tumour extends beyond the uterus, within the pelvis (Fig. 444)
T2a	IIA	Tumour involves adnexa (Fig. 444)
T2b	IIB	Tumour involves other pelvic tissues (Fig. 445)
T3	III	Tumour infiltrates abdominal tissues
T3a	IIIA	One site (Fig. 446)
T3b	IIIB	More than one site (Fig. 447)
N1	IIIC	Metastasis to regional lymph nodes
T4	IVA	Tumour invades bladder or rectum (Fig. 448)
M1	IVB	Distant metastasis

Note
Simultaneous tumours of the uterine corpus and ovary/pelvis in association with ovarian/pelvic endometriosis should be classified as independent primary tumours.

Schematic illustration of tumour 5 cm or less in greatest dimension. — **Fig. 442**

Schematic illustration of tumour more than 5 cm in greatest dimension. — **Fig. 443**

Schematic illustration of tumour extends beyond the uterus, within the pelvis. — **Fig. 444**

Schematic illustration of tumour involves other pelvic tissues. — **Fig. 445**

Schematic illustration of One site for IIIA FIGO stage in T3 category. — **Fig. 446**

Schematic illustration of more than one site for IIIB FIGO stage in T3 category. — **Fig. 447**

Schematic illustration of tumour invades bladder or rectum. — **Fig. 448**

Adenosarcoma

TNM Clinical Classification

T – Primary Tumour

TNM Categories	FIGO Stage	Definition
T1	I	Tumour limited to the uterus
ΌT1a	ΌIA	ΌTumour limited to the endometrium/endocervix (Fig. 449)
ΌT1b	ΌIB	ΌTumour invades to less than half of the myometrium (Fig. 450)
ΌT1c	ΌIC	ΌTumour invades more than half of the myometrium (Fig. 451)
T2	II	Tumour extends beyond the uterus, within the pelvis
ΌT2a	ΌIIA	ΌTumour involves adnexa (Fig. 444)
ΌT2b	ΌIIB	ΌTumour involves other pelvic tissues (Fig. 445)
T3	III	Tumour involves abdominal tissues
ΌT3a	ΌIIIA	ΌOne site (Fig. 446)
ΌT3b	ΌIIIB	ΌMore than one site (Fig. 447)
N1	IIIC	Metastasis to regional lymph nodes
T4	IVA	Tumour invades bladder or rectum (Fig. 448)
M1	IVB	Distant metastasis

Note
Simultaneous tumours of the uterine corpus and ovary/pelvis in association with ovarian/pelvic endometriosis should be classified as independent primary tumours.